The invention relates to detectors for detecting hot spots in a region.
Flame detectors have been designed for and used in various environments. E.g., Dunbar U.S. Pat. No. 4,988,884 describes a flame detector specifically designed for use in aircraft. So-called "combi" aircraft, which use a deck for passengers or cargo or both, have special detection requirements. In these aircraft it is desired to detect a flame or hot spot (increased temperature region) for the different possible uses of the aircraft cabin. When used for cargo, there often are cargo containers that take up most of the space in the cabin and block a ceiling mounted detector from viewing anything except the tops of the containers; it is necessary to be able to detect either flames or hot spots on the container tops, which are very near to the ceiling. When the cargo containers are not present (whether used for passengers, palletized cargo, or even livestock), the cabin is much more open, and the region that needs to be viewed is much larger.